Alkaline earth metals have applications as components of ferroelectric, ferromagnetic and super-conducting materials. Deposition of these metals has often been difficult, however, because many of the precursor compounds, particularly compounds of barium, strontium and calcium, typically have low volatilities or significant tendencies to decompose at volatilization temperatures.
.beta.-diketonate compounds, including those of alkaline earth metals, have been reported to be sufficiently volatile for such depositions, particularly when substituent groups of the .beta.-diketonate are fluorocarbons. These compounds, however, are generally still not sufficiently stable for most chemical vapor deposition processes. Also, the fluorinated species often cause fluorine to be deposited with the alkaline earth metal thereby diminishing the purity and performance of deposited films.
A need exists, therefore for new methods and apparatus for depositing alkaline earth metal compounds which overcome or minimize the aforementioned problems.